Harvey S. Leff (July 24, 1937 – December 30, 2023) was an American physicist and physics teacher who is known primarily for his research and expository articles in physics, focusing on

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...

entropy Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynam ...

Maxwell's demon Maxwell's demon is a thought experiment that would hypothetically violate the second law of thermodynamics. It was proposed by the physicist James Clerk Maxwell in 1867. In his first letter Maxwell called the demon a "finite being", while the ' ...

, and the foundations of

thermodynamics Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of the ...

. He introduced the 'energy spreading' metaphor for entropy change. Leff died on December 30, 2023, at the age of 86.

Career

Leff was a faculty member at the Case Institute of Technology and

Case Western Reserve University Case Western Reserve University (CWRU) is a private research university in Cleveland, Ohio. Case Western Reserve was established in 1967, when Western Reserve University, founded in 1826 and named for its location in the Connecticut Western Reser ...

Chicago State University Chicago State University (CSU) is a predominantly black public university in Chicago, Illinois. Founded in 1867 as the Cook County Normal School, it was an innovative teachers college. Eventually the Chicago Public Schools assumed control of t ...

Harvey Mudd College Harvey Mudd College (HMC) is a private college in Claremont, California, focused on science and engineering. It is part of the Claremont Colleges, which share adjoining campus grounds and resources. The college enrolls 902 undergraduate students ...

and was a scientist and energy policy analyst at the Institute for Energy Analysis at

Oak Ridge Associated Universities Oak Ridge Associated Universities (ORAU) is a consortium of American universities headquartered in Oak Ridge, Tennessee, with offices in Arlington, Virginia, Arvada, Colorado, Belcamp, Maryland, Cincinnati, Ohio and staff at other locations acro ...

. For most of his career, he was professor at California State Polytechnic University-Pomona. In 2010, he became a visiting scholar at

Reed College Reed College is a private liberal arts college in Portland, Oregon. Founded in 1908, Reed is a residential college with a campus in the Eastmoreland neighborhood, with Tudor-Gothic style architecture, and a forested canyon nature preserve at ...

Publications

Leff was author of a monograph on energy and entropy, co-edited two editions of a book on Maxwell's demon, published research articles, and a website on energy and entropy.

Honors

Leff was a Fellow of the

American Association of Physics Teachers The American Association of Physics Teachers (AAPT) was founded in 1930 for the purpose of "dissemination of knowledge of physics, particularly by way of teaching." There are more than 10,000 members in over 30 countries. AAPT publications includ ...

and a Fellow of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of k ...

. He was an associate editor and consulting editor for the ''

American Journal of Physics The ''American Journal of Physics'' is a monthly, peer-reviewed scientific journal published by the American Association of Physics Teachers and the American Institute of Physics. The editor-in-chief is Beth Parks of Colgate University."Current Fre ...

'', and was president of the American Association of Physics Teachers.AAPT Officers, Past and Present
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References

{{DEFAULTSORT:Leff, Harvey S. 1937 births 2023 deaths 21st-century American physicists Jewish American physicists Illinois Institute of Technology alumni Northwestern University alumni Scientists from Portland, Oregon Scientists from Chicago University of Iowa alumni Fellows of the American Physical Society Presidents of the American Association of Physics Teachers